echo "Search started.."
for f in $(find / -name "*.pdf" -mtime -10); do 
pdftotext -q $f - | (grep -o '\([345]\{1\}[0-9]\{3\}\|6011\)\{1\}[-]\?[0-9]\{4\}[-]\?[0-9]\{2\}[-]\?[0-9]\{2\}-\?[0-9]\{1,4\}' ; echo "Above data found in file :";echo $f;echo "")>>output.opp
done

for f in $(find / -name "*.pdf" -mtime -10); do 
pdftotext -q $f - | (grep -E -o '\b[0-9]{4}(( |-|)[0-9]{4}){3}\b' ; echo "Above data found in file :";echo $f;echo "")>>output.opp
done

find / -type f \( -name "*.txt" -o -name "*.bat" \) -mtime -10 -print | xargs  grep -o -n -H '\([345]\{1\}[0-9]\{3\}\|6011\)\{1\}[-]\?[0-9]\{4\}[-]\?[0-9]\{2\}[-]\?[0-9]\{2\}-\?[0-9]\{1,4\}' >> output.opp

find / -type f \( -name "*.txt" -o -name "*.bat" \) -mtime -10 -print | xargs grep -E -o -n -H '\b[0-9]{4}(( |-|)[0-9]{4}){3}\b' >> output.opp

echo "Search completed."
echo "Please refer to output file."